HEIC to JPG convert embedded thumbnails are lost

[FredN9]

Trying to mass convert Apple iPhone IOS HEIC Files to JPG but embedded thumbnails get lost.
Tried playing with jpg settings for "rebuild embedded EXIF thumbnail" but didn't work.
HEIC File shows embedded thumbnail exist in the file with icon.
Rebuild option in metadata doesn't seem to fix the issue.

Issue appears both in XnConvert and in XnView MP lastest version on Windows 10 (1.99 and 1.6.4 64 bits)

Tried with other tool CopyTransHEICforWindows v2.000 and this one is working fine but only works from explorer context menu per folder.

Is this a bug or is HEIC embedded EXIF Thumbnail is not supported ?
Is there another way to embedded thumbnails in existing jpg files?
Looks like this is a great tool for this mass migration project.

Regards, Fred

[xnview]

currently embedded thumbnail for HEIC is not supported, please send me a sample file

[FredN9]

currently embedded thumbnail for HEIC is not supported, please send me a sample file

Doesn't want to upload heic file as attachment. Can I do this in PM or other means ?

Regards, Fred

[xnview]

yes by PM

[FredN9]

Is there a way to add an embedded EXIF thumbnail in a jpg file ?
For example with XnView MP ? When I use Rebuild nothing seems to happen and no embedded thumbnail icon appears
Or are there other tools available to do this ?

Regards, Fred

[xnview]

For example with XnView MP ? When I use Rebuild nothing seems to happen and no embedded thumbnail icon appears

Embedded thumbnail should be added with it

[FredN9]

For example with XnView MP ? When I use Rebuild nothing seems to happen and no embedded thumbnail icon appears

Embedded thumbnail should be added with it

It doesn't, at least I don't see the icon appearing in XnView MP
Is there another way to check if there is an embedded thumbnail ?
Can you check if it's a bug ?

Regards,
Fred

[xnview]

please send me the file?